There are 2 major aims for this multidisciplinary investigation. 1. To evaluate the potential for adrenal tissue characterization in patients with clinically silent adrenal masses using imaging tests which are both functional (6B-131I-Iodomethyl-19-Norcholest-5(10)-EN-3-B-OL [NP-59] adrenal cortical scintigraphy) and morphologic (magnetic resonance imaging [MRI]. 2. In patients with known adrenal hyperfunction and an adrenal mass to evaluate the tissue characterization potential of MRI. Encompassed within the scope of the specific aims are the following objectives. 1. To optimize MR pulse sequences and quantitative data for tissue characterization purposes. 2. To determine whether MRI can reliably distinguish nonhyperfunctioning adrenal adenomas from adrenal metastases. 3. To determine whether MRI can reliably distinguish nonhyperfunctioning adrenal adenomas from hyperfunctioning adrenal cortical and medullary neoplasms. 4. To delineate using NP-59 scintigraphy the function of the abnormal adrenal gland incidentally detected by CT in the non-oncologic and oncologic patient. 5. To determine the accuracy of NP-59 scintigraphy in evaluation of the clinically silent adrenal mass, particularly in distinguishing nonhyperfunctioning adenoma from metastasis. 6. To correlate the differential function of the normal vs. abnormal adrenal by quantitative NP-59 scintigraphy. 7. To compare efficacy of the functional (NP-59) and morphologic (MRI) tests in evaluating the clinically silent adrenal mass. 8. In a small group of patients with clinically silent adrenal masses to compare quantitative data from MRI obtained at both high (1.5-2.OT) and low (.35T) field strengths. In summary, hypotheses based on our preliminary investigations are: 1. Both MRI and NP-59 scintigraphy will prove to be extremely useful in adrenal tissue characterization and differential diagnosis. 2. These tests should obviate the need for biopsy in a subset of patients with adrenal masses.